package com.atguigu.gulimall.product.service.impl;

import org.springframework.stereotype.Service;

import java.util.Comparator;
import java.util.List;
import java.util.Map;
import java.util.stream.Collectors;

import com.baomidou.mybatisplus.core.conditions.query.QueryWrapper;
import com.baomidou.mybatisplus.core.metadata.IPage;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.atguigu.common.utils.PageUtils;
import com.atguigu.common.utils.Query;

import com.atguigu.gulimall.product.dao.CategoryDao;
import com.atguigu.gulimall.product.entity.CategoryEntity;
import com.atguigu.gulimall.product.service.CategoryService;


@Service("categoryService")
public class CategoryServiceImpl extends ServiceImpl<CategoryDao, CategoryEntity> implements CategoryService {

    @Override
    public PageUtils queryPage(Map<String, Object> params) {
        IPage<CategoryEntity> page = this.page(
                new Query<CategoryEntity>().getPage(params),
                new QueryWrapper<CategoryEntity>()
        );

        return new PageUtils(page);
    }

    @Override
    public List<CategoryEntity> listWithTree() {
        // 查询大类的分类列表
        List<CategoryEntity> entities = baseMapper.selectList(null);
        // 找出所有的1级分类
        List<CategoryEntity> level1Menus = entities.stream()
                .filter(categoryEntity ->  categoryEntity.getParentCid() == 0)
                .map((menu) -> {
                    menu.setChildren(getChildrens(menu,entities));
                    return menu;
                })
                .sorted(Comparator.comparingInt(items -> items.getSort() == null ? 0 : items.getSort()))
                .collect(Collectors.toList()) ;
        return level1Menus;
    }

    /**
     *  @author: wuyu
     *  @Date: 2021/3/7 11:06 下午
     *  @Description: 查找出所有菜单的子菜单
     */
    private List<CategoryEntity> getChildrens(CategoryEntity root, List<CategoryEntity> all) {
               List<CategoryEntity> childList = all.stream()
                       .filter(item -> item.getParentCid().equals(root.getCatId()))
                       .map(menu -> {
                           menu.setChildren(getChildrens(menu,all));
                           return menu;
                       })
                       .sorted(Comparator.comparingInt(items ->
                            items.getSort() == null ? 0 : items.getSort()
                       ))
                       .collect(Collectors.toList()) ;
               return childList;
    }

}